Apparatus for producing shielded ribbon-type cables



Dec. 10,1968 M. GRISWOLD APPARATUS FOR PRODUCING SHIELDED RIBBON-TYPE CABLES Original Filed Feb.

2 Sheets-Sheet 1 16. 5. INVENTOR.

LEE M /SWQLD A7770NEYS Dec. 10, 1968 L. M. GRISWOLD 3,415,096

APPARATUS FOR PRODUCING SHIELDED RIBBON-TYPE CABLES Original Filed Feb. 1, 1965 2 Sheets-Sheet 2 INVENTOR. ZZZ M 63/55 410 BY A? fi s United States Patent 3,415,096 APPARATUS FOR PRODUCING SHIELDE RIBBON-TYPE CABLES Lee M. Griswold, Pasadena, Calif., assignor to Digital Sensors Inc., Los Angeles, Calif., a corporation of California Original application Feb. 1, 1965, Ser. No. 432,063, now abandoned. Divided and this application Feb. 9, 1967, Ser. No. 633,312.

8 Claims. (Cl. 72196) ABSTRACT OF THE DISCLOSURE An apparatus for subjecting ribbon type electrical cable sandwiched between copper sheets to a pair of entermeshing rotating gears to impart a hill and dale configuration to the assembly without appreciably stretching the copper of the cable or sheets for greater flexibility and long life.

The present application is a division of my copending application Serial Number 432,063, filed February 1, 1965, which is a continuation-in-part of my patent application Serial Number 176,730, filed March 1, 1962, and assigned to the same assignee, both applications having been abandoned.

The present invention relates to apparatus for the construction of a shielded ribbonor tape-type cable.

There are commercially available ribbon or tape-type cables wherein a plurality of spaced ribbon-type condoctors are embedded in plastic insulating material. It is oftentimes desirable to electrostatically shield such cables without appreciably increasing the size or stiffness of the same. This is accomplished in the instant construction by cementing or otherwise suitably aflixing thin metal, preferably copper, sheets to opposite sides of the ribbon or tape cable and passing the assembly through a pair of intermeshing rotating gears to impart a generally hill and dale configuration to the assembly, such configuration resembling a corrugation, with each ridge defining each corrugation extending in a direction transverse to the embedded conductors. While corrugated assemblies are employed in the prior art to impart strength and rigidity to a structure, the present arrangement results in a greater amount of flexibility in the finished assembly than is otherwise the case when the shielding material is not formed with such hills and dales.

It is therefore an object of the present invention to provide an improved shielded cable of this character featured by its flexibility.

Another object of the present invention is to provide new concepts whereby this new shielded assembly may be made simply, quickly and economically.

Another object of the present invention is to provide apparatus whereby an improved shielded cable of this character may be produced.

The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. This invention itself, both as to its organization and manner of operation, together with further objects and advantages thereof, may be best understood by reference to the following description taken in connection with the accompanying drawings, in which:

FIG. 1 is a perspective view illustrating elements used in the instant construction.

FIG. 2 is a transverse sectional view through an assembly during one stage of operation.

FIG. 3 is an enlarged view illustrating the manner in which the assembly illustrated in FIG. 2 is subsequently formed.

FIG. 4 is a plan view of a portion of the finished shielded cable assembly.

FIG. 5 is a view taken substantially along line 5-5 of FIG. 4.

FIGS. 6-9 illustrate apparatus embodying features of the present invention used in forming the cable of FIG. 4, FIG. 6 being a perspective view of the apparatus, and FIGS. 7, 8 and 9 being sectional views taken substantially as indicated by corresponding lines 7--7, 8-8 and 9-9 in FIGS. 6, 7 and 8, respectively.

FIG. 1 illustrates a ribbonor tape-type cable 10 which is commercially available and which is shielded. Such cable 10, as illustrated, has ten separated ribbon-type conductors 11 embedded in plastic insulating material 12. FIG. 1 also shows a pair of copper sheets, tapes or ribbons 14 and 15 which serve to electrostatically shield the conductors 11 from external electrostatic influences.

These metal strips 14 and 15, as illustrated in FIG. 2, are secured to opposite sides of the tape cable 10 by adhesive 16 and 17.

In order to increase the flexibility of the assembly shown in FIG. 2, it is subjected to an operation illustrated in FIG. 3 which involves passing such assembly between a pair of intermeshing and rotating gears 20 and 21 to produce a particular type of configuration to the assembly as illustrated in FIGS. 4 and 5. The copper sheets and tapes 14 and 15 are thus deformed to give the general appearance of a corrugated structure in which there are successive and equally spaced hills 23 and dales 24.

It will be seen that the ridges defining such hills extend transversely to the direction in which the conductors 11 extend. The assembly 26 shown in FIG. 4 is representative of a tape having a width of 1 inch. The number of ridges per one-inch length of the tape is approximately fifteen in number. The result of this deformation produced by the step illustrated in FIG. 3 is that the finished assembly exhibits greater flexibility than does the assembly shown in FIG. 2. This is quite important in uses of the finished assembly, considering the fact that it serves to make electrical connections of electrical equipment with the assembly being required to extend around corners or obstructions. Also, it is considered that the operation shown in FIG. 3 results in a better bonding of the shielding tapes 14 and 15 to the cable 10.

While the shields 14 and 15 may first be secured, as illustrated in FIG. 2, prior to subjecting the same to the teeth of gears 20 and 21, as illustrated in FIG. 3, the shields may be secured by adhesive simultaneously as the assembly is being deformed between the gears 20' and 21.

The apparatus used for forming such hills and dales is illustrated in detail in FIGS. 6-9 and includes a rectangular base member 30 to which a rectangular mounting plate 32 is secured by fasteners 34. Two pairs of vertically and parallel extending rectangular plates 36, 37 and 38, 39 are each releasably secured at their lower ends to the mounting plate 32 using a single Allen head type bolt 40 for each one of the plates; and at the upper ends such plates are maintained spaced by spacer blocks 46, 48, the spacer blocks 46, 48 being likewise secured by fasteners 47 in which case two fasteners per plate are provided.

A pair of lower spaced bearing blocks 50, 52 is secured to the mounting plate 32 using a plurality of screwthreaded fasteners, as exemplified by the fastener 54 in FIG. 8. Such spaced bearing blocks 50, 52 rotatably support a corresponding reduced end portion of a toothed roller 58, and one of such end portions 58A is extended through the bearing block and mounts a gear 60 and handle 62.

Also rotatably supported on the spaced stationary bearing blocks 50, '52 is a smaller toothed roller 64 having reduced end portions, exemplified by the roller reduced end portion 64A, rotatably supported in circular apertured portions of the blocks 50, 52, the toothed portions of rollers 58 and 64 being in meshing contacting relation whereby manual turning of handle 62 results in rotation of the toothed roller 64.

Another like but adjustably positionable roller system involving a large toothed roller 70 in meshing contact with a smaller toothed roller 72 is provided. The toothed roller 70 has reduced end portions rotatably supported in spaced bearing blocks 74, 76 each of which is secured to an adjustably positionable rectangular bar 78 by fasteners exemplified by the fastener 80 shown in FIG. 8. An end portion 70A of roller 70 is sufficiently prolonged to mount a gear 84 in meshing contacting end engagement with gear 60. The smaller toothed roller 72 has reduced end portions exemplified by the end portion 72A rotatably supported in bearing blocks 76, 76, whereby turning of the handle 62 results also in rotation of the larger roller 70 and the smaller toothed roller 72 in meshing contact engagement therewith. However, this arrangement is such that while the toothed portions of the smaller rollers 64, 72 contact the toothed portions of their corresponding drive rollers 58 and 70, there is no contact between the toothed portions of the smaller rollers 64, 72, i.e. the ends of the toothed portion of one enters the space between the ends of the toothed portion of the other without contact, as exemplified in FIG. 3.

This relation between the smaller rollers 64, 72 may be adjusted to accommodate different tape thicknesses by the adjustment mechanism now described.

The bar 78 which mounts the bearing blocks 74, 76 is provided with two spaced and undercut blocks 90, 92 secured to bar 78 by fasteners exemplified by the fastener 94 in FIG. 8. Besides being undercut, as illustrated, each of the blocks 90, 92 is provided with an open-ended slotted portion exemplified by the slotted portion 90A in FIG. 8 to receive an udercut portion of the end of a corresponding one of two adjustment screws 96, 98 which are correspondingly threaded in the spacer bars 46, 48 and which are provided with enlarged knurled end portions 96A, 98A. Thus, 'by turning the knurled portions 96A, 98A, the vertical position of the upper toothed roller 72 with respect to roller 64 may be adjusted. To obtain this adjustment with accuracy, cooperating guide means between the bearing blocks 74, 50 and also between blocks 76, 52 are provided. Such guide means is exemplified in FIG. 7 and includes a pair of pins 100, 102 threaded in the lower bearing block 50 and extending upwardly in sliding engagement within a corresponding bushing 104, 106 threaded in upper bearing block 74. This particular guide structure also allows convenient partial disassembly for purposes now described.

In some instances, it is desirable to impart the hill and dale configuration to a tape which already has large end connectors incapable of passing through the apparatus as such. :In this case, the rollers 72, 64 are separated in a partial disassembly of the apparatus accomplished by loosening one or both of the lower fastening screws 40, 40 and correspondingly pivoting the end assemblies 108, 110 about the axis of loosened screws 40, 40 to effect a disengagement of the undercut lower ends of screws 96, 98 from the slotted portions of blocks 90, 92 in which case the bar 78 may be raised on the vertical guide pins 100, 102 sufficiently to allow passage of the enlarged tape end between the rollers 62, 72. When this is done, the assemblies 108, 110 are pivoted to again establish engagement between the ends of screws 96, 98 and blocks 90, 92 and the screws 40, 40 are tightened.

It will also be seen that the threaded bushings 104, 196 and threaded pins 100, 102 also allow accurate alignment and establish a minimum separation between the toothed rollers 64, 72.

The present arrangement obviates ditficulties encountered in feeding a flat sheet between two meshed gears wherein meshing of the teeth tends to stretch the sheet material resulting from a number of teeth in mesh to various degrees simultaneously while the teeth are engaging further. The present arrangement avoids a situation wherein adjoining teeth grasp the sheet while other teeth are engaging further and thereby avoids stretching of the sheet. Stretching a cable is not desirable as it weakens and stresses the copper conductors. In this regard, it is noted that in this instance corrugating rollers with a small number of teeth, eight or less in number, are used. In this way only one or two teeth are used at one time, and the action is thus essentially a process of folding, i.e. of making one fold or corrugation complete to its full depth before interaction of the next teeth. While this obviates the stretching problem, another problem is introduced which is solved in a unique manner as now explained.

Since the flat cables are a few inches wide, there is the problem of a small diameter roller (small number of teeth) not being supported in the middle area of the fiat cable and thus not corrugating with adequate pressure in the middle area. The small diameter corrugating or folding roller is given support along its full length by the larger diameter toothed roller which serves not only as a drive member but also as a support member.

Also, it is noted that the exterior driving gears 60, 84

are indexed so that the corrugating or folding rollers 64, 72 are maintained in accurate mesh even though they are far from engaging. This positive meshing of the roller teeth is deemed necessary to prevent damage to the cable. 1 In use, the apparatus is adjusted so that the spacing between roller teeth is less than the thickness of .the tape and is so adjusted that the formed or corrugated tape assembly, measured transversely from peak to peak, is one and one-half times the thickness of the initial flat tape assembly, using a roller with eight teeth to obtain the above indicated folding action.

Also preferably the metal shielding sheets are secured to the tape by a nonsolidifying adhesive, i.e. one which does not set or solidify, whereby during this folding action slight movement between the shielding sheets and tape may occur.

While the particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from this invention in its broader aspects and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.

I claim:

1. Tape folding apparatus of the character described, comprising: a first large toothed roller; a second toothed roller, smaller than said first roller, meshing with and contacting said first roller throughout the length of said smaller roller to provide a support and a drive for the same; a third large toothed roller; a fourth toothed roller, smaller than said third roller, and meshing with and contacting said third roller throughout the length of said fourth roller to provide a support and drive for the same; and means for driving said first and third rollers in synchronism.

2. Apparatus as set forth in claim 1, in which the number of toothed portions on said second and third rollers are no greater than eight in number.

3. Apparatus as set forth in claim 1, including a stationary support; means rotatably mounting said first and second rollers on said support; bearing means; means rotatably mounting said third and fourth rollers on said bearing means; and means adjustably supporting said bearing means on said support whereby the spacing between said second and fourth rollers may be adjusted.

4. Tape folding apparatus of the character described, comprising a stationary support member; a first pair of spaced bearing blocks mounted on said support member;

a first toothed roller; a second toothed roller meshing with and contacting said first roller, said first and second rollers being rotatably supported in said bearing blocks; a second pair of spaced bearing blocks; a third toothed roller; a fourth toothed roller; said third and fourth rollers being rotatably supported in said second pair of bearing blocks and meshing and contacting each other; cooperating guide means between said first and second pair of bearing blocks; and means on said support member and effective to adjust individually each one of said second pair of bearing blocks.

5. Tape folding apparatus of the character described, comprising a stationary support member; a first toothed roller; a second toothed roller contacting and meshing with said first toothed roller; means rotatably supporting said first and second rollers on said support member; a first frame pivoted on said support member; a second frame pivotally supported on said support member; a third toothed roller; a fourth toothed roller contacting and meshing with said third roller; a pair of bearing means for said third and fourth rollers for rotatably supporting the same; a bar interconnecting said pair of bearing means; and screw-threaded means on each of said frames and each being attachably and detachably coupled to said bar; said screw-threaded means being detached from said bar upon pivotal movement of a corresponding one of said frames mounting a corresponding one of said screw-threaded members.

6. Tape folding apparatus of the character described, comprising: a support member; a pair of spaced bearing blocks on said support member; a first toothed roller; a second toothed roller intermeshing with and contacting said first roller; said first and second rollers each having their opposite ends rotatably supported in a corresponding one of said bearing blocks; a pair of support frames pivotally mounted on said support member; a second pair of bearing blocks, each within a corresponding one of said frames; cooperating guide means between said first pair of bearing blocks and said second pair of bearing blocks; a bar interconnecting each of said second pair of bearing blocks; said second pair of bearing blocks being within a corresponding one of said frames; a third toothed roller; a fourth toothed roller intermeshing with and contacting said third toothed roller; said third and fourth rollers having their opposite ends rotatably supported in a corresponding one of said second pair of bearing blocks; screw-threaded means mounted on each of said frames; means releasably securing said screwthreaded means to said bar; said last mentioned means being detachable upon pivotal movement of a corresponding one of said frames; a first gear connected to said first roller; a second gear connected to said third roller and meshing with said first gear; and means for rotating said first gear.

7. Apparatus as set forth in claim 6, in which said cooperating guide means includes a bushing and a pin slidably mounted in said bushing; said bushing being adjustably mounted in one of said bearing blocks, and said pin being adjustably mounted in a different bearing block.

8. Apparatus as set forth in claim 7, in which said frames are pivoted about an axis which is perpendicular to the axes of said rollers; and said pin has its axis extending mutually perpendicular to the axes of said rollers and to the pivoting axes of said frames.

References Cited UNITED STATES PATENTS 1,098,144 5/1914 Baumgartner 72-187 1,365,258 1/1921 Lundin 72---196 1,900,032 3/1933 Worthington 72-243 CHARLES W. LANHAM, Primary Examiner.

US. Cl. X.R. 72-243, 363, 385 

